Taylor Swift has recalled in court the moment she felt a disgraced DJ's hand on her butt as her assault and battery trial continues.

The singer took the stand early on Thursday, and told the Denver, Colorado court there's still no doubt in her mind former KYGO radio host David Mueller touched her inappropriately during a meet-and-greet backstage at a 2013 show in the city.

"It was a definite grab, (a) very long grab," "the pop star said. "It was long enough for me to be completely sure it was intentional. He stayed on my bare a** cheek as I lurched away from him uncomfortably. The first couple of milliseconds, I thought it must be a mistake. I moved to the side very quickly… It was a very shocking thing that I have never dealt with before" He grabbed my a** underneath my skirt. It was underneath my skirt."

"After this happened, a light switched off in my personality," she added. "I just said, in a monotone voice, thank you for coming and then they were gone."

Mueller sued Swift in 2015, claiming she'd falsely accused him of groping her and cost him his job. Swift, who is seeking only $1 in damages, counter"-"sued for assault and battery.

The singer's mother, Andrea, took the stand on Wednesday and fought back tears as she recalled her daughter telling her about the butt grab.

"I knew what happened, I heard it from her, I heard it from my daughter's mouth," she said, before pointing at Mueller in the courtroom and adding, "He sexually assaulted her, right there, that guy."

"She (Taylor) couldn't believe that after he grabbed her, that she thanked them for being there," Andrea recalled. "It was just destroying her that she said that… As a parent it made me question why I taught her to be so polite in that moment."

The singer's mom went on to explain they opted not to report the alleged assault to the police, because they didn't want the incident to "define" Taylor"s life.

"I was upset to the point where I wanted to vomit and cry at the same time," she testified. "We felt it was imperative to let his employers know what happened."

Mueller also hit the stand on Wednesday, and told his own lawyer, Gabe McFarland, he purposefully closed his hand during the photo opportunity with Taylor, "so as to not poke" her.

McFarland concluded, "Mueller has been hurt and wants his good name back and he wants to be fairly compensated for income he lost and ability to earn income in the future."